linux-kernel - [PATCH 1/3] cpufreq: stats: Remove redundant cpufreq_cpu

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Date:	Tue, 25 Feb 2014 19:38:33 -0800
From:	Saravana Kannan <skannan@...eaurora.org>
To:	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	Viresh Kumar <viresh.kumar@...aro.org>
Cc:	linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-arm-msm@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	"Saravana Kannan" <skannan@...eaurora.org>
Subject: [PATCH 1/3] cpufreq: stats: Remove redundant cpufreq_cpu_get() call

__cpufreq_stats_create_table always gets pass the valid and real policy
struct. So, there's no need to call cpufreq_cpu_get() to get the policy
again.

Change-Id: I0136b3e67018ee3af2335906407f55d8c6219f71
Signed-off-by: Saravana Kannan <skannan@...eaurora.org>
---

Viresh/Rafael,

These 3 patches is the approximate code I have in mind.

Approximate because:
* I inserted one question as a comment into the code.
* If the patch doesn't have any bugs, the plan is to remove
  cpufreq_generic_get() and references to it.

This takes care of the "don't advertise before it's ready for use" rule.

Viresh,

I think the locking updates needs to be done in addition to this.

Regards,
Saravana

 drivers/cpufreq/cpufreq_stats.c | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 5793e14..e4bd27f 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -185,7 +185,6 @@ static int __cpufreq_stats_create_table(struct cpufreq_policy *policy,
 {
 	unsigned int i, j, count = 0, ret = 0;
 	struct cpufreq_stats *stat;
-	struct cpufreq_policy *current_policy;
 	unsigned int alloc_size;
 	unsigned int cpu = policy->cpu;
 	if (per_cpu(cpufreq_stats_table, cpu))
@@ -194,13 +193,7 @@ static int __cpufreq_stats_create_table(struct cpufreq_policy *policy,
 	if ((stat) == NULL)
 		return -ENOMEM;
 
-	current_policy = cpufreq_cpu_get(cpu);
-	if (current_policy == NULL) {
-		ret = -EINVAL;
-		goto error_get_fail;
-	}
-
-	ret = sysfs_create_group(&current_policy->kobj, &stats_attr_group);
+	ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
 	if (ret)
 		goto error_out;
 
@@ -243,11 +236,8 @@ static int __cpufreq_stats_create_table(struct cpufreq_policy *policy,
 	stat->last_time = get_jiffies_64();
 	stat->last_index = freq_table_get_index(stat, policy->cur);
 	spin_unlock(&cpufreq_stats_lock);
-	cpufreq_cpu_put(current_policy);
 	return 0;
 error_out:
-	cpufreq_cpu_put(current_policy);
-error_get_fail:
 	kfree(stat);
 	per_cpu(cpufreq_stats_table, cpu) = NULL;
 	return ret;
-- 
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